With the new 3WA series, Siemens is updating its Sentron portfolio of air circuit breakers. As a core element of low-voltage switchboards, they reliably protect electrical installations in buildings, infrastructures and industrial facilities from damage caused by short circuits, ground faults or overload faults. At the same time, the new 3WA circuit breakers meet all low-voltage power distribution requirements in digital environments.
They support software-based planning and engineering, digital testing and monitoring, and seamless integration in automation and IoT systems. For the first time, upgrades can be completed 100 percent digitally. Users simply download new features from the Internet and add them using an app.
Siemens circuit breakers are designed for 30,000 operating cycles while requiring only one inspection per year. With a potential service life above 100 years, their practical life averages approximately 10 years.
“Distributed energy systems, digitalization and the Internet of Things will all place ever higher and more complex demands on electrical power distribution,” according to John O’Gorman, Low Voltage Products Manager at Siemens Ireland. “Our new circuit breakers are well equipped to handle these challenges. They are flexible enough to adapt to the tasks of tomorrow without needing to be swapped out”
When technological requirements change, it is easy to add new features to the electronic trip unit (ETU600) installed in the 3WA air circuit breakers using the Sentron “powerconfig” commissioning software and a USB or communication port. The features are available online and are continually expanded by Siemens. Users benefit from high investment protection.
High reliability in distributed energy systems
Today, a third of all energy generated worldwide comes from renewable sources. By its nature, wind and solar energy can cause the grid voltage to fluctuate, which can lead to costly failures in industrial and building operations. 30 to 40 percent of all unplanned equipment downtimes can be traced back to inadequate supply quality. The new 3WA circuit breakers can handle voltage fluctuations of up to 10 percent, reliably preventing false tripping and failures.
As active grid participants, infrastructure and industrial systems produce, store and use their own energy or feed it into the grid. This requires technology capable of handling bidirectional power flows. The 3WA air circuit breakers are now able to automatically adapt their protection algorithms to the actual direction of flow, thus maximizing the protection they offer for smart grid prosumers.
End-to-end digital lifecycle
CAx data can be used to create digital twins of the 3WA air circuit breakers. The intuitive “powerconfig” software is used for parameterization. The “powerconfig” software allows for remote monitoring of the current contact states and sensors of all switches and hence early fault detection. Integrated communication and measuring functions capture energy data and transfer it to automation and cloud-based energy management platforms as well as medium-voltage systems. Switched Ethernet functionality makes it possible to use multiple communication protocols such as Profinet and Modbus TCP at the same time, allowing users to benefit from fast and powerful data transfers.
The 3WA air circuit breakers are available in three sizes with nominal currents from 630 to 6,300 A for AC applications and in one size with nominal currents of 1,000, 2,000 and 4,000 A for DC applications.
Download the White Paper “Cybersecurity with 3WA air circuit breakers” at